Income Taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Taxes [Abstract]
New York City unincorporated business tax (in hundredths)	4.00%
Computation of equity in net income attributable to AllianceBernstein Unitholders [Abstract]
Net income attributable to AllianceBernstein Unitholders	$ 116,725	$ 114,516
Multiplied by: weighted average equity ownership interest (in hundredths)	35.40%	37.50%
Equity in net income (loss) attributable to AllianceBernstein Unitholders	41,371	42,997
Computation of income tax [Abstract]
AllianceBernstein qualifying revenues	499,129	482,586
Multiplied by: weighted average equity ownership interest for calculating tax (in hundredths)	29.30%	27.70%
Multiplied by: federal tax (in hundredths)	3.50%	3.50%
Federal income taxes	5,112	4,666
State income taxes	100	100
Total income taxes	$ 5,212	$ 4,766
Effective tax rate (in hundredths)	12.60%	11.10%
Changes in components for calculation of income tax [Abstract]
Increase in net income attributable to AllianceBernstein Unitholders (in hundredths)	1.90%
Decrease in equity in net income attributable to AllianceBernstein Unitholders (in hundredths)	(3.80%)
Change in AllianceBernstein qualifying revenues (in hundredths)	3.40%
Increase in income taxes (in hundredths)	9.40%